title: Preparation of submicrometer monodispersed magnetic silica particles using a novel water in oil microemulsion: properties and application for enzyme immobilization.
abstract: The synthesis of monodispersed magnetic silica nanoparticles (MSN) is described using a water-in-oil reverse microemulsion system that does not require the use of co-surfactants. Sodium silicate, Tween 20 as a neutral surfactant and 1-butanol as the organic phase were used. There are several advantages of the proposed method including a saturation magnetization value of 10 emu/g for the particles obtained, uniformity of size and that they are easily functionalized to bind urease covalently. Moreover, the intra-day, inter-day and long-term stability results confirm that the procedure was successful and the enzyme-linked MSNs were stable over repeated uses and storage retaining more than 75% activity after 4 months.
authors.affiliation: IQUIMEFA-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 Piso 3º, 1113, Buenos Aires, Argentina.
authors.forename: Maria Victoria
authors.initials: MV
authors.lastname: Tuttolomondo
authors.forename: Maria Emilia
authors.initials: ME
authors.lastname: Villanueva
authors.forename: Gisela Solange
authors.initials: GS
authors.lastname: Alvarez
authors.forename: Martín Federico
authors.initials: MF
authors.lastname: Desimone
authors.forename: Luis Eduardo
authors.initials: LE
authors.lastname: Díaz
mesh_terms: D001709:Biotechnology / Q000379:methods; D004655:Emulsions; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism*; D008280:Magnetics; D053758:Nanoparticles; D012822:Silicon Dioxide; D014510:Urease / Q000737:chemistry / Q000378:metabolism*
chemical_list: D004655:Emulsions; D004800:Enzymes, Immobilized; D012822:Silicon Dioxide; D014510:Urease